Electromagnet Metals

Problem Scenario

Electromagnets are widely used in business today. Examples of commercial use of electromagnets include moving scrap metal, generating electricity, drive motors for freight trains, and lifting high speed trains off their rails. Finding better core material could allow electromagnets to be built that would be stronger, lighter, and or less expensive.

Broad Question

What is an electromagnet?

Specific Question

How do different core materials affect the strength of an electromagnet?

Hypothesis

By using different core materials while keeping the voltage and the amount of wire wrap the same, some materials will create stronger electromagnets than others.

Graph of Hypothesis

Variables

Independent Variable: Types of metal cores
Dependent Variable: The strength of the electromagnet (the weight it can hold in grams)
Variables That Need To Be Controlled: The number of coils, type of wire, amount of wire, strength of battery, and the mass of metal core.

Vocabulary List That Needs Explanation

Electromagnet- a core of a magnetic surrounded by a coil of wire through which an electric current is passed to magnetize the core
Ferromagnetism- noting or pertaining to a substance, as iron, that below a certain temperature, the Curie point, can possess magnetization in the absence of an external magnetic field; noting or pertaining to a substance in which the magnetic moments of the atoms are aligned.
Magnetic Permeability- A measure of the ability of a substance to sustain a magnetic field, equal to the ratio between magnetic flux density and magnetic field strength.

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General Plan

In my experiment I will be changing the type of core material of an electromagnet and observing which one makes the electromagnet strongest. I will be measuring the strength of the electromagnet by seeing how many paper clips it can lift. The core material that allows the electromagnet to lift the most paperclips will be the strongest. I will be setting up a work area on a work bench in my basement. No one will disturb my work area.

Potential Problems And Solutions

A potential problem will be finding core materials in a way that will allow me to make them as close to the same size and mass as possible. This may also create a problem for making the number of wire wraps and the total number of wire wrapped around the core the same.

Safety Or Environmental Concerns

Three safety or environmental concerns are being shocked by the electromagnet wiring, having the electromagnet overheat and burn your hands when you are holding it, and caustic materials leaking from the battery.

Experimental Design

What is your experimental unit?

One electromagnet.

Number Of Trials:

I will repeat the experiment 4 times with each core.

Number Of Subjects In Each trial:

There will be 4 subject cores in each trial.

Number of Observations:

I will take 16 observations total.

When data will be collected

The data will be collected by February 25.

Where will data be collected?:

The data will be collected at my work area in my basement.

Resources and Budget Table

Item	Number needed	Where I will get this	Cost
6 volt battery	1	Staples	$13.79
22 gauge bare copper wire	15 feet	My house	$0.00
3 in. long 1/4 in. in diameter steel bolt	1	Home Depot	$2.00
3 in. long 1/4 in. in diameter iron rod	1	Home Depot	$2.00
3 in. long 1/4 in. in diameter brass/copper bolt	1	Home Depot	$3.00
tri-fold poster board display	1	Dollar Tree	$1.00
alligator clips	2	My House	$0.00

Detailed Procedure
1.) Purchase a 6 volt battery, two alligator clips, about 15 feet of 22 gauge bare copper wire, and a 3 inch long 1/4 of an inch diameter rod of iron, steel, and copper.
2.) Wrap the copper wire from end to end around each of the iron, steel and copper cores, and leave 12 inches of wire extra from each end, removing insulation from the ends of the wires. Then remove one of the cores, set it aside to be the air core, and re-wrap the rod that you just used.
3.)Connect the alligator clips to the battery terminals.
4.) One at a time, attach the ends of the wire of each core to the battery by way of the alligator clips.
5.) Place small paper clips into a small, non-metal bowl.
6.) One at a time dip one end of the each core into the bowl of paper clips, lift it out, and count the number of paper clips it lifted. Record the number of lifted clips, remove them, and then repeat this process four times for each core.
7.) Calculate the average of the lifts of each core and graph the results in a column chart.

Diagram

Photo List

~electromagnet materials
~an electromagnet
~an electromagnet picking up items
Time Line

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Data Table

CORE	NUMBER OF PAPER CLIPS LIFTED
IRON
trial 1	39
trial 2	32
trial 3	38
trial 4	34
Average	35.75
BRASS
trial 1	0
trial 2	0
trial 3	0
trial 4	0
Average	0 could lift steel wool sample
STEEL
trial 1	50
trial 2	65
trial 3	62
trial 4	58
Average	58.75
AIR
trial 1	0
trial 2	0
trial 3	0
trial 4	0
Average	0 could not lift steel wool sample

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Data Analysis

All Raw Data

Graphs

Photos

Results

The steel core magnet lifted an average of almost 59 paperclips. The iron core magnet lifted an average of almost 36 paperclips. The brass and air core magnets lifted no paperclips, but I was able to show that the brass core electromagnet had some magnetism by its ability to lift a light piece of steel wool, something that the air core magnet couldn't do.

Conclusion

I had expected that the iron core magnet would be the strongest followed by the steel core, then the brass core, and lastly the air core. I was surprised then, that the steel magnet seemed stronger than the iron core, and was also surprised how weak both the brass core and air core magnets were. In conclusion, different core materials do affect the strength of an electromagnet.

Discussion

My data showed that the electromagnetic cores with stronger magnetic permeability tended to be stronger. However, I did not get exactly the results that I predicted in my hypothesis. The iron core was not quite as strong as the steel core as I had had expected. The brass core was much weaker than I had expected, and the air core had so little strength I could not collect any useful data about its strength. Since I had carefully constructed each core and measured their lifting ability four times each, I believe the data that I had collected is accurate. If I were to perform this experiment again, I would use larger cores, and more wraps of thicker wire to get more lifting ability from all four cores to see if the results were closer to my hypothesis.

Benefit to Community and/or Science

Since electromagnets are used in industry, computers, transportation, and much more, creating electromagnets that are both small and powerful could lead to better computer devices, medical industries, and zero gravity high speed trains. Although I was only able to use common materials for my electromagnet cores, I wanted to demonstrate how scientists are working to create new cores for electromagnets with magnetic inductance that would produce tiny, but powerful "super magnets"

Background Research

Magnetism is a property of materials that causes them to react to a magnetic field by being attracted to it, or repelled away from it. There are two types of magnets. Permanent magnets have constant magnetic fields caused by a property called ferromagnetism. An electromagnet, the other type of magnet, has its magnetism produced by the flow of an electric currant. Its magnetic field disappears when the currant stops.
A simple electromagnet is made of a coil of insulated wire wrapped around an iron core. The strength of an electromagnet is proportional to the amount of currant. An electric currant flowing in a wire creates a magnetic field around the wire. If the wire is wound into a coil, it concentrates the magnetic field with many turns of wire lying side by side. The magnetic field of all the turns of wire pass through the center of the coil creating a strong magnetic field there. The more coils of wire, the stronger the magnetic field. Stronger magnetic fields can be produced if the core of the coil is a ferromagnetic material such as iron. The higher the magnetic permeability of the core, the stronger the electromagnet will be. Superconducting electromagnets use windings cooled with liquid helium to conduct currant without electrical resistance to produce intense magnetic fields. Electromagnets are widely used in devices such as electric motors, generators, electric bells, loud speakers and earphones. Electromagnets are also used in tape recorders, VCRs, and computer hard disks. Medical devices such as MRIs use electromagnets. In business, large electromagnets are used to lift scrap iron, and separate metallic wastes from non-metallic wastes.

References

~ "Electromagnet." Wikipedia. Wikimedia Foundation, 03 May 2013. Web. 12 Mar. 2013.
~ "How Electromagnets Work." HowStuffWorks. N.p., n.d. Web. 12 Mar. 2013.
~ "How Do I Make an Electromagnet?" How Do I Make an Electromagnet? N.p., n.d. Web. 14 Mar. 2013.

Abstract

Electromagnets are increasingly important in our lives because they are used for many things.The magnetism of an electromagnet is created when a current flows through coils of wire wrapped around a core. For this experiment I attempted to keep the current and size of the wire coils and cores the same, and change only the material of the core.Since the strength of the magnetism should increase with the magnetic permeability of the core material, I expected the electromagnets to rank in strength from iron, to steel, then brass, and last air cores. When I tested each core, the average of the four lifts showed the steel core strongest, followed by the iron core.The brass core was unable to lift a clip (it could barely lift a small piece of steel wool) and the air core couldn't even do that.There may have been a problem with the material that we used as the "iron" core, and I would change the experiment to use a bigger coil to get measurable data from the brass and air core magnets.